The code in install-printf.c and unit-printf.c for these is pretty much
the same and very generic. Let's move this all over to the generic
specifier.c, and share the implementations.
The test was written so far under the assumption that if two mounts are
placed onto the same location the "upper" mount is listed later in
/proc/self/mountinfo. This appears not to be guaranteed however, as
running the tests in a normal nspawn shows.
This patch fixes that: it reverses the hashmap of mounts we build:
instead of keying by path, we key by mnt_id, and if we notice that
path_get_mnt_id() doesn't match what a line in /proc/self/mountinfo
says, we use the returned ID to check if maybe another line agrees.
Fixes: #7431
This is a simple wrapper around name_to_handle_at_loop() and
fd_fdinfo_mnt_id() to query the mnt ID of a path. It uses
name_to_handle_at() where it can, and falls back to to
fd_fdinfo_mnt_id() where that doesn't work.
This is a best-effort thing of course, since neither name_to_handle_at()
nor the fdinfo logic work on all kernels.
First of all, let's rename it to read_etc_hostname(), to make clearer
what kind of configuration it actually reads: the file format defined in
/etc/hostname and nothing else.
Secondly: let's port this to use read_line(), i.e. the new way to read
lines from a file in a safe, bounded way.
Thirdly: let's strip leading/trailing whitespace from what we are
reading. Given that we are already pretty lenient what we read (comments
and empty lines), let's be permissive regarding whitespace too.
Fourthly: let's actually validate the hostname when reading it. So far
we tried to make it valid, but that's not always possible (for example,
we can't make an empty hostname valid, ever).
So far I avoided adding license headers to meson files, but they are pretty
big and important and should carry license headers like everything else.
I added my own copyright, even though other people modified those files too.
But this is mostly symbolic, so I hope that's OK.
All this function does is place some data in an in-memory read-only fd,
that may be read back to get the original data back.
Doing this in a way that works everywhere, given the different kernels
we support as well as different privilege levels is surprisingly
complex.
Linux doesn't have faccess(), hence let's emulate it. Linux has access()
and faccessat() but neither allows checking the access rights of an fd
passed in directly.
This path to ping is compatible with both debian-like and usr-merged
distros. This keeps the test simple, and should thus pass everywhere.
Fixes: #7267
Lennart Poettering
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
tblume
Dimitri John Ledkov
John Lin